F15 / SU / Mig Nose Pitch Oscillation

[Avio]

Just bought the FC3, wanting very much to fly cool jets like F15C, etc. But I notice there is much nose pitch oscillation up and down whenever I try settling down after some maneuvering. Is this normal? Are the real jets like this too? It is like the nose pitch wouldn't settle quickly on the attitude that I want. For example, if I nose down a few degrees then neutralise stick, the nose would pitch up and oscillate a little before settling down. This makes for difficult precision flying / targeting.

 

Any advice highly appreciated. Thanks.

 

Avio

[Azrayen]

Which aicraft were you flying?

Which version of DCS?

 

If russian bird, no artificial pitch stability; you have to trim.

[Avio]

I'm using DCS World, and FC3. The planes in question are F-15C, Su-27, and the Mig-29.

 

They all exhibit that unstable nose pitching motion.

[Zabuzard]

I'm not 100% sure what you mean but if you're talking about the tendency of aircrafts to constantly pitch up OR down depending on altitude, attitude and height than it's normal.

 

That occures due to the power of the turbines and some other factors, your strick "neutral" position is somewhat calibrated to a power setting of them but if you change speed or fly high (where air density changes) the neutral setting isn't a neutral setting anymore and you're pitching up or down.

To counteract this one uses trimming which simply changes the neutral position of the stick (you can watch it move if you use trimming). For trimming there are settable keys in the settings.

One would trim so the aircraft flys straight in neutral position or use the "horizontal stabilization - autopilot" also known as panic mode which trims the aircraft automaticly for a stable straight flight (autopilot uses trimming to control the aircraft).

 

In propeller aircrafts (like P-51D) this "problem" is much heavier because lack of FCS systems and because the propeller spins in one direction which causes the aircraft to constantly slip to right or left if air density or propeller power changes which results in constantly trimming the rudder.

 

Be aware that in 1.2.8 the trimming of the F-15C is buggy at the moment and won't work currently.

[Avio]

Thanks fellows. I'm familiar with what trimming is about. But what didn't appear normal was the oscillations of the nose pitch each time following even a slight intended change of the nose pitch up or down. Don't see this happening in other fighter sims. I, would expect the onboard FCS to have taken care of most flight regimes to ensure solid precision on where one intends to point the nose at.

 

Had noticed this in the earliest Lock-On package. Abandoned that because of this issue. Now years later on to FC3, and I'm sad to still see this in there. I would really love to fly the F-15C well in this sim.

 

I do have the A-10C too, and thankfully, that one flies superbly and I enjoy it very much.

[Weta43]

Have you tried the F-15 in the open Beta ? The F-15 PFM doesn't suffer from this (to me anyway).

Re the Su-27, I remember reading an account by an (F-18 I think) American active service pilot who was taken up in an Su-27 & given the stick - he said it was very sensitive in pitch.

[Zabuzard]

In the Su-27 you can adjust the sensitivity of the control inputs, remember it's fully fly-by-wire using the Flight Control System (FCS).

 

But yeah the Su-27 is sensitive in pitch because it actually can do that better than others. But the FCS stabilizes the aircraft all the time so it won't oscillate, it's sensitive but precise.

 

The aerodynamic form and the slat-flaperon system was built to be better in pitch than others. You can also see this at the close-quarter R-73 IR missiles which can be launched without pointing the nose to the enemy or the Helmet Mounted Display targeting system. This gives the Su-27 superiority in dogfights.

 

Here you can see where to adjust the FCS sensitivity in the real Su-27:

 

Edited April 23, 2014 by Zabuza